Battery module with improved connection structure between electrode leads and method for manufacturing the same

Abstract

Provided is a battery module in which a connection structure between electrode leads is changed to prevent a heat generation phenomenon when overcharged and to allow easy connection and disconnection between secondary batteries, and a method for manufacturing the same. The battery module according to the present disclosure includes a secondary battery stack formed by stacking a plurality of secondary batteries having electrode leads, wherein each electrode lead protrudes from the corresponding secondary battery, and each electrode lead has a bent part, and the bent parts of opposite-polarity electrode leads of neighboring secondary batteries are stacked with an elastic body interposed therebetween, and the corresponding stacked part is fastened by an insulating bolt including a washer, with the elastic body being compressed.

What is claimed is: 
     
       1. A battery module comprising:
 a secondary battery stack including a plurality of stacked secondary batteries each extending in a vertical direction and having two electrode leads of opposite polarities, 
 wherein the two electrode leads of each secondary battery protrude from the respective secondary battery, each electrode lead having a bent part extending in a horizontal direction perpendicular to the vertical direction, and 
 the bent part of one of the electrodes of each of the secondary batteries is stacked with a washer and with the bent part of one of the electrodes of opposite polarity of an adjacent one of the secondary batteries, with an elastic body interposed between the bent parts of the ones of the electrodes of the adjacent ones of the secondary batteries, and with an insulating bolt compressing the elastic body and fastening the bent parts of the ones of the electrodes of the adjacent ones of the secondary batteries to one another. 
 
     
     
       2. The battery module according to  claim 1 , wherein a bus bar is disposed below the stacked bent parts of the adjacent ones of the secondary batteries and is fastened to the stacked bent parts by the insulating bolt. 
     
     
       3. The battery module according to  claim 2 , wherein the bent parts and the bus bar of the adjacent ones of the secondary batteries each have a bolt hole extending therethrough in the vertical direction, and the insulating bolt is coupled with a nut below the bus bar and extends through the washer and the bolt hole. 
     
     
       4. The battery module according to  claim 2 , wherein the bent parts of the adjacent ones of the secondary batteries have a bolt hole extending therethrough in the vertical direction and the bus bar has a bolt tab, and the insulating bolt is coupled to the bolt tab and extends through the washer and the bolt hole. 
     
     
       5. The battery module according to  claim 1 , wherein the elastic body of the adjacent ones of the secondary batteries has a ring shape and extends around the insulating bolt. 
     
     
       6. The battery module according to  claim 1 , wherein the elastic body of the adjacent ones of the secondary batteries is disposed symmetrically on two opposite sides of the insulating bolt. 
     
     
       7. The battery module according to  claim 1 , wherein the washer is configured to melt when a temperature of the battery module exceeds a predetermined limit, and the elastic body becomes uncompressed and forces apart the bent parts of the adjacent ones of the secondary batteries, thereby creating a gap between the stacked bent parts and breaking an electrical connection between the stacked bent parts. 
     
     
       8. A method for manufacturing a battery module, comprising:
 preparing a plurality of secondary batteries each having two electrode leads of opposite polarities, each lead having a bolt hole extending therethrough; 
 bending an end of each of the electrode leads in a horizontal direction; 
 stacking the bent part of one of the electrodes of each of the secondary batteries with a washer and with the bent part of one of the electrodes of opposite polarity of an adjacent one of the secondary batteries, with an elastic body interposed between the bent parts of the ones of the electrodes of the adjacent ones of the secondary batteries such that the bolt holes are aligned; and 
 fastening the bent parts of the ones of the electrodes of the adjacent ones of the secondary batteries and the washer to one another with an insulating bolt extending through the bolt hole and compressing the elastic body. 
 
     
     
       9. The method for manufacturing a battery module according to  claim 8 , wherein a bus bar is disposed below the stacked bent parts of the adjacent ones of the secondary batteries and is fastened to the stacked bent parts by the insulating bolt. 
     
     
       10. The method for manufacturing a battery module according to  claim 9 , wherein the bus bar of the adjacent ones of the secondary batteries each has a bolt hole extending therethrough in a vertical direction perpendicular to the horizontal direction, and the insulating bolt is coupled with a nut below the bus bar and extends through the washer and the bolt hole. 
     
     
       11. The method for manufacturing a battery module according to  claim 9 , wherein the bus bar of the adjacent ones of the secondary batteries each has a bolt tab, and the insulating bolt is coupled to the bolt tab and extends through the washer and the bolt hole. 
     
     
       12. The method for manufacturing a battery module according to  claim 8 , wherein the elastic body of the adjacent ones of the secondary batteries has a ring shape and extends around the insulating bolt. 
     
     
       13. The method for manufacturing a battery module according to  claim 8 , wherein the elastic body of the adjacent ones of the secondary batteries is disposed symmetrically on two opposite sides of the insulating bolt. 
     
     
       14. The method for manufacturing a battery module according to  claim 8 , wherein when a temperature of the battery module exceeds a predetermined limit, the washer melts and the elastic body is uncompressed and forces apart the bent parts of the adjacent ones of the secondary batteries, thereby creating a gap between the stacked bent parts and breaking an electrical connection between the stacked bent parts.